Legg-Calvé-Perthes Disease

Legg-Calvé-Perthes disease is a childhood hip disorder in which the blood supply to the femoral head is temporarily disrupted, leading to weakening and gradual reshaping of the ball of the hip joint. The condition can affect hip movement, walking, and the long-term shape of the joint.

The disease develops through several stages and can vary considerably between children. Some cases heal with a nearly spherical femoral head, while others may leave residual deformity that can increase the risk of hip stiffness, impingement, or osteoarthritis later in life.

What Is Legg-Calvé-Perthes Disease?

Legg-Calvé-Perthes disease is a form of osteonecrosis affecting the developing femoral head in children.

The femoral head is the rounded upper end of the thigh bone that fits into the hip socket. When its blood supply is temporarily interrupted, the bone becomes weaker and may flatten or fragment before gradually healing.

What Causes Legg-Calvé-Perthes Disease?

The exact cause is not fully understood.

The condition appears to result from temporary loss of blood flow to the growing femoral head, but the reason this happens is often unknown.

In most children, there is no single injury or event that explains the disease.

At What Age Does Perthes Disease Occur?

Legg-Calvé-Perthes disease most commonly develops during childhood, often between approximately 4 and 10 years of age.

Age at onset is important because younger children generally have greater potential for the femoral head to remodel during growth.

Is Perthes Disease More Common in Boys?

Yes.

Legg-Calvé-Perthes disease is more common in boys, although girls can also be affected.

When the condition occurs in girls, careful assessment is important because skeletal maturity and remaining growth may influence prognosis.

Can Both Hips Be Affected?

Yes, but the disease more commonly affects one hip.

Bilateral involvement can occur, sometimes at different times.

When both hips are involved symmetrically or atypically, other skeletal or metabolic conditions may also need to be considered.

What Are the Symptoms of Legg-Calvé-Perthes Disease?

Possible symptoms include:

• Limping
• Hip pain
• Groin pain
• Thigh pain
• Knee pain
• Reduced hip movement
• Stiffness
• Pain after physical activity
• Muscle weakness around the hip

Can Perthes Disease Cause Knee Pain?

Yes.

Hip disorders in children can sometimes present as pain around the thigh or knee because pain can be referred from the hip joint.

Persistent knee pain with limping or limited hip motion should therefore include examination of the hip.

Why Does a Child Limp?

Limping can result from pain, restricted hip movement, muscle weakness, or altered mechanics of the hip joint.

In some children, limping is the first noticeable sign even before significant pain develops.

Which Hip Movements Are Commonly Limited?

Hip abduction and internal rotation are commonly reduced.

Loss of these movements can be an important clinical finding and may also increase the risk that the femoral head moves less freely within the hip socket.

What Happens to the Femoral Head?

The femoral head can pass through a period of weakening, fragmentation, healing, and remodeling.

During the weaker stages, mechanical loading can influence the shape of the femoral head.

The goal of treatment is often to preserve hip motion and help the femoral head remain as well contained within the socket as possible while healing occurs.

What Are the Stages of Perthes Disease?

The disease typically progresses through several phases:

How Long Does Perthes Disease Last?

The disease process can continue for several years.

The exact duration varies according to age, disease severity, and the biological response of the femoral head.

Because healing is gradual, long-term follow-up is often necessary.

How Is Legg-Calvé-Perthes Disease Diagnosed?

Diagnosis begins with a history, physical examination, and imaging of the hips.

The examination may assess:

• Walking pattern
• Hip range of motion
• Hip abduction
• Internal rotation
• Leg-length difference
• Muscle strength
• Hip, thigh, and knee tenderness

Are X-Rays Important?

Yes.

Pelvic and hip X-rays are central to diagnosis, staging, and follow-up.

They can demonstrate changes in femoral head density, fragmentation, collapse, lateral extrusion, healing, and final shape.

Can Early X-Rays Be Normal?

Yes.

In the earliest phase, radiographic changes may be subtle.

When clinical suspicion remains high despite normal or unclear X-rays, additional imaging may sometimes be useful.

When Is MRI Used?

MRI can identify early changes in the femoral head before they become obvious on standard X-rays.

It may also help evaluate the extent of femoral head involvement, cartilage shape, containment, and other hip structures in selected cases.

What Does Containment Mean?

Containment refers to how well the femoral head remains positioned within the acetabulum, which is the socket of the hip.

A well-contained femoral head has a better opportunity to remodel within the rounded shape of the socket during healing.

Loss of containment can allow part of the weakened femoral head to move laterally outside the socket and become more deformed.

Why Is Hip Range of Motion Important?

Good hip motion, particularly abduction, helps maintain containment of the femoral head.

Significant stiffness can make containment more difficult and may influence treatment decisions.

What Is Femoral Head Extrusion?

Femoral head extrusion describes lateral displacement of part of the femoral head beyond the normal coverage of the acetabulum.

Increasing extrusion can be associated with loss of containment and a higher risk of deformity.

How Is the Severity of Perthes Disease Classified?

Several classification systems are used to describe the extent and stage of disease.

These systems help estimate prognosis and support treatment planning, but no classification should be used without considering the child's age, hip motion, containment, and overall clinical picture.

What Is the Lateral Pillar Classification?

The lateral pillar classification evaluates how much of the lateral portion of the femoral head maintains height during the fragmentation stage.

It is commonly divided into groups A, B, and C, with greater collapse generally associated with a less favorable prognosis.

What Is the Herring Classification?

The Herring classification is another name for the lateral pillar classification.

It is most useful during the fragmentation stage when the degree of lateral pillar involvement can be reliably assessed.

What Is the Catterall Classification?

The Catterall classification describes the proportion of the femoral head involved by the disease.

It historically divided Perthes disease into groups according to increasing extent of involvement.

Modern treatment decisions generally combine classification with age, containment, mobility, and other prognostic factors.

Which Factors Affect Prognosis?

Important factors may include:

• Age at disease onset
• Amount of femoral head involvement
• Degree of collapse
• Hip range of motion
• Femoral head containment
• Presence of lateral extrusion
• Stage at diagnosis
• Final shape of the femoral head

Why Is Age Important?

Younger children generally have more growth remaining and therefore greater potential for remodeling.

Older children may have less time for the femoral head to reshape before skeletal maturity.

Age is important, but it should not be considered alone.

Does Every Child Need Surgery?

No.

Many younger children with mild disease, good hip motion, and satisfactory containment can be managed without surgery.

Treatment is individualized according to disease severity and the risk of progressive deformity.

What Is the Goal of Treatment?

The main goals are to preserve hip movement, reduce pain, maintain or improve containment, and help the femoral head heal in the most favorable shape possible.

Treatment cannot instantly restore the blood supply or directly reverse the biological stages of the disease.

Non-Surgical Treatment for Legg-Calvé-Perthes Disease

Should Running and Jumping Be Restricted?

High-impact activities may be temporarily reduced when the hip is painful or when the femoral head is particularly vulnerable to deformation.

Activity recommendations should be individualized rather than applying permanent restrictions to every child.

Can Swimming or Cycling Be Helpful?

Lower-impact activities such as swimming or cycling may allow children to remain active while reducing repetitive impact on the hip.

Suitability depends on pain, hip motion, and the stage of disease.

Is Physical Therapy Important?

Yes.

Maintaining hip flexibility is an important part of treatment.

Therapy commonly focuses on preserving abduction, internal rotation, muscle strength, and an efficient walking pattern.

Can Exercise Restore the Femoral Head?

No.

Exercise cannot directly restore damaged bone or change the biological course of osteonecrosis.

Its role is to preserve mobility, muscle function, and favorable hip mechanics while the disease heals.

Are Crutches Sometimes Used?

Yes.

Temporary reduction of weight bearing with crutches may be considered when pain is significant or when limiting mechanical stress is clinically appropriate.

Long-term weight-bearing restrictions are not automatically necessary for every child.

Are Braces or Casts Used?

Containment braces or casts have historically been used to position the hips in abduction and improve femoral head coverage.

Their use today is selective and depends on age, severity, hip mobility, treatment philosophy, and the individual characteristics of the disease.

When Is Surgery Considered?

Surgery may be considered when there is a substantial risk of losing containment or developing significant femoral head deformity.

Factors that may influence surgical consideration include:

• Older age at onset
• More extensive femoral head involvement
• Loss of containment
• Lateral extrusion
• Progressive deformity
• Reduced hip motion
• Specific radiographic risk signs

What Is Containment Surgery?

Containment surgery aims to improve the relationship between the femoral head and the acetabulum while the disease is active.

The goal is to keep the vulnerable femoral head more deeply positioned within the socket so that the acetabulum can help guide remodeling.

What Is a Femoral Varus Osteotomy?

Femoral varus osteotomy is a procedure in which the upper femur is surgically realigned to improve containment of the femoral head within the acetabulum.

The bone is repositioned and stabilized with implants while healing occurs.

It is used only in selected patients.

What Is Pelvic Osteotomy?

A pelvic osteotomy changes the orientation or shape of the acetabulum to improve coverage of the femoral head.

Procedures such as a Salter-type osteotomy may be considered in selected children depending on age, hip anatomy, and containment.

Femoral Osteotomy vs Pelvic Osteotomy

Can Both Femoral and Pelvic Surgery Be Needed?

In selected complex cases, combined procedures may be considered.

The decision depends on hip anatomy, severity of extrusion, age, mobility, and the amount of correction required.

Does Surgery Cure Perthes Disease?

Surgery does not stop the biological disease process itself.

Its purpose is generally to improve containment, alignment, or hip mechanics while the femoral head heals and remodels.

What Are the Risks of Surgery?

Possible risks include:

• Infection
• Bleeding
• Delayed bone healing
• Implant-related problems
• Overcorrection or undercorrection
• Hip stiffness
• Persistent deformity
• Leg-length difference
• Need for additional surgery

What Happens After Surgery?

Rehabilitation depends on the procedure performed and the child's healing.

Weight bearing may be restricted temporarily, and physical therapy may be used to restore hip movement and strength.

Follow-up X-rays are used to evaluate bone healing and progression of the Perthes disease.

Can the Femoral Head Become Deformed?

Yes.

During the fragmentation stage, the weakened femoral head can flatten, enlarge, or lose its normal spherical shape.

The final shape is one of the major factors influencing long-term hip function.

What Is Coxa Magna?

Coxa magna describes enlargement of the femoral head that can remain after Perthes disease.

An enlarged or irregular femoral head may not fit perfectly within the acetabulum and can alter hip mechanics.

What Is Coxa Breva?

Coxa breva refers to a relatively shortened femoral neck that can develop as a residual deformity after Perthes disease.

It can contribute to altered hip mechanics and weakness of the abductor muscles.

Can Perthes Disease Cause Leg-Length Difference?

Yes.

Growth disturbance of the proximal femur can lead to a difference in leg length.

The clinical importance depends on the amount of discrepancy and its effect on walking and pelvic balance.

Can Perthes Disease Cause Hip Impingement Later?

Yes.

Residual femoral head and neck deformity can create abnormal contact between the femur and acetabulum.

This can lead to femoroacetabular impingement, reduced hip motion, labral damage, and pain in adolescence or adulthood.

Can Perthes Disease Cause Hip Osteoarthritis?

It can increase the risk.

An irregular or poorly congruent femoral head can concentrate pressure within the hip joint and contribute to cartilage degeneration over time.

However, not every person with a history of Perthes disease develops early osteoarthritis.

Can Adults Have Problems From Childhood Perthes Disease?

Yes.

Adults may develop pain, stiffness, limited motion, impingement, labral problems, leg-length difference, or osteoarthritis related to residual hip deformity.

Treatment depends on the remaining joint shape and degree of cartilage damage.

What Is the Stulberg Classification?

The Stulberg classification describes the final shape and congruence of the hip after Perthes disease has healed.

More spherical and congruent hips generally have a more favorable long-term mechanical relationship than markedly flattened or incongruent hips.

Can Hip Preservation Surgery Be Used in Older Patients?

Yes, in selected adolescents and young adults with residual Perthes deformity and preserved joint cartilage.

Procedures may address femoral head-neck impingement, abnormal femoral alignment, acetabular coverage, or other mechanical problems.

The procedure must be selected according to the individual anatomy.

Is Hip Replacement Ever Needed?

Total hip replacement may eventually be considered in adults who develop advanced painful hip osteoarthritis after previous Perthes disease.

It is not a treatment for the active childhood stage of the disease.

Can Perthes Disease Be Prevented?

There is currently no established method to prevent typical Legg-Calvé-Perthes disease because the exact cause of the temporary blood-supply disturbance remains unclear.

Can a Child Return to Sports?

Many children can eventually return to sports, but activity should be adjusted according to pain, hip mobility, disease stage, and femoral head condition.

High-impact sports may be limited during vulnerable phases, while lower-impact activities can sometimes be continued.

Why Is Long-Term Follow-Up Important?

The final hip shape develops gradually over years.

Follow-up helps monitor femoral head remodeling, hip containment, range of motion, leg length, and the development of residual deformity.

Some problems may only become apparent as the child approaches skeletal maturity.

When Should a Child Be Evaluated?

Orthopedic evaluation may be appropriate when a child has:

• Persistent limping
• Hip or groin pain
• Repeated unexplained knee pain
• Loss of hip movement
• Pain after activity
• A previously diagnosed Perthes disease requiring follow-up
• Increasing stiffness or difficulty walking

When Is Urgent Evaluation Needed?

Perthes disease itself is usually not an emergency.

However, a child with severe sudden hip pain, inability to bear weight, fever, significant trauma, marked swelling, or acute illness should be evaluated promptly because infection, fracture, or another urgent hip condition may be present.

Legg-Calvé-Perthes Disease Treatment in Antalya

Treatment of Legg-Calvé-Perthes disease begins by evaluating the child's age, stage of disease, hip range of motion, femoral head involvement, and containment within the acetabulum.

Younger children with mild disease and good hip movement may only require observation, activity modification, and rehabilitation. Maintaining hip abduction and internal rotation is an important part of conservative management.

Children with more extensive involvement or loss of containment may require surgical procedures such as femoral or pelvic osteotomy. Treatment aims to protect hip function and support the most favorable femoral head remodeling possible during growth.

Frequently Asked Questions About Legg-Calvé-Perthes Disease

What is Legg-Calvé-Perthes disease?

It is a childhood hip disorder caused by temporary disruption of blood supply to the developing femoral head.

What are the first signs of Perthes disease?

Limping, reduced hip movement, and hip, groin, thigh, or knee pain are common early findings.

Can Perthes disease cause knee pain?

Yes. Pain from the hip can be referred to the thigh or knee.

Does Perthes disease affect both hips?

It usually affects one hip, although bilateral disease can occur.

Can Perthes disease heal without surgery?

Yes. Many younger children with mild disease and good containment can be treated without surgery.

Why is hip movement important?

Good hip abduction and internal rotation help maintain femoral head containment within the socket.

What is containment treatment?

Containment treatment aims to keep the femoral head positioned within the acetabulum during healing so that remodeling can occur in a more favorable environment.

When is surgery considered?

Surgery may be considered in selected children with greater disease involvement, loss of containment, progressive extrusion, or a higher risk of residual deformity.

Can Perthes disease cause arthritis later in life?

Residual femoral head deformity can increase the risk of hip osteoarthritis, but long-term outcome varies considerably between patients.

Is long-term follow-up necessary?

Yes. The hip continues to remodel throughout growth, so periodic assessment helps evaluate the final shape, movement, containment, and function of the joint.